Nationals acquire closer Mark Melancon from the Pirates

The Washington Nationals acquired the back-end reliever they need Saturday afternoon, acquiring Pirates closer Mark Melancon for Felipe Rivero and minor league left-hander Taylor Hearn. The Nationals will get cash back in the deal, according to a person familiar with the situation. They have, therefore, addressed their greatest need without giving up any of their most valued prospects in one of the most significant deadline acquisitions in their D.C. history.

Melancon, 31, will close for the Nationals, according to a person with direct knowledge of their plans, who said Jonathan Papelbon has been told about the deal, and was “a great team player.” Papelbon will, presumably, now be moved into a role other than closer for the first time since his rookie year — and will do so with the ninth-most saves in baseball history, second to Francisco Rodriguez among active players. Papelbon suffered two losses in two games earlier this week, then had to be pulled in the ninth inning of Thursday’s game with two men on in a save situation.